Transmission mechanism for starters.



JJL- TRUMBLE..

TRANSMISSION MECHANISM FOR STARTERS.

APPLICATION FILED NOV. 20. 1916. I 1,256,746. Patented Feb.19, 1918..

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JOHN T. TRUMIBLE, OF FREEPORT,

ILLINOIS.

TRANSMISSION MECHANISM- FOR STARTERS.

To all whom it may concern:

Be it known that 1, JOHN T. TnUMBnn, a citizen of the United States of America, residing at Freeport, in the county of Stevenson and State of Illinois, have invented certainnew and useful Improvements in Transmission Mechanism for Starters, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to a mechanism adapted to couple a rotor and a driven or follower member and is especially adapted to couple a starter for an explosive engine with the latter, the action being automatic and the device being so disposed as to effect its purpose with a minimum number of parts and an action that avoids the liability to breakage or injury to either the starter or motor.

The invention consists in the matters hereinafter set forth, and more particularly pointed out in the appended claims.

In the drawings,

Figu'rel is a view, partially in elevation and partially broken away and in section, of a device that embodies features of the invention, shown in initial positionyand Fig. 2 is a similar view showing the device in engaged position.

As herein indicated, starting motor 1 be of any approved type operates a drive shaft 2, the outer end portion of which may be supported in a suitable bearing 3, and the intermediate portion of which either carries or has formed thereon a worm thread or screw 4 of comparatively coarse pitch.

A bushing 5 is engaged by the worm so as to run easily and freely thereon. A friction sleeve 6 is non-rotatably and longitudinally reciprocable on the bushing 5, spline 7 or like means preventing inter-rotation of the parts and a spring 8 that encircles the bushing being in adjustable compression between the sleeve 6 and a tension nut 9 screwthreaded on to the bushing. A flange stop 10 limits the movement of the sleeve 6. i

The face of the sleeve 6, which is slightly beveled and may have a renewable friction lining 11 of suitable material, is adapted to be brought into engagement with the peripheral surface 12 of the engine fly-wheel or like rotatable part of the motor to which the starter is to beconnected, by suitable Specification of Letters Patent. JP'atagntedl Feb, 19, 1918. Application filed November 20, 1916. Serial No. 132,361.

disposition of the shaft 2 in relation to the engine wheel. This further momentarily locks the sleeve from rotation'and holds it from shifting, while the bushing travels along the worm to a'point where the resultant compression of the spring imposes sufficient end thrust to cause the parts to rotate in unison. They may even assume the position shown in Fig. 2 with the bushing contacting with the stop flange. Thus a firm, frictional engagement is had with the yielding and cushioning effect of the spring accommodating slight irregularities and safeguarding against sudden shock. When the motor picks up and overruns the starter, the sleeve and bushing are given a retrograde movement on the worm, drawing clear of the driven member and returning to initial position.

Thus a driving mechanism is obtained that acts automatically to maintain the proper driving and idling relations between the rotor and follower member. It is particularly effective between a starter and the motor which it operates, the automatic engagement and release making it peculiarly adaptable for such use.

'Obvi0usly, changes in the details of con-' struction may be made without departing from'the spirit of my invention and I do not care to limit myself to any particular form or arrangement of parts.

hat I claim is positively driven member, a follower mem her, a member foffrictional engagement with the follower member rotatably and longitudinally shiftable on the positively driven member, such friction member in contact with a fol- 10,4. 1. A coupling mechanism. comprising a and means for yieldingly holding lower member and in non-rotatable engagement with the driving member when in such contact, the connection between the positively driven member and frictional engaging member causing the latter to shift on the positively driven member until arrested from such movement by frictional engagement with a follower member.

2. The combination with a follower member, of a positively rotated driving member, and means for frictionally engaging the follower member that is rotatable and longitudinally reciprocable on the driving member, the engagement between the driving member and friction engaging means being such that inertia of the latterprevents rotation thereof'relative to the drivin member and causes axial movement along t e latter into contact with the follower member, and means yieldingly holding the frictional engaging means .both in contact with the follower member and in non-rotatable engagement with the driving member when in contact with the follower member.

3. The combination with a follower member, of a positively rotated driving member,

' meansfor frictionally engaging the follower member in screwthreaded en'gag'ement on the driving member, and means on the frictional means for yieldingly holding'the latter'in contact with the follower member, and a non-rotatable engagement with the driving member when in such contact, the inertia of the frictional engaging means preventing rotation of the frictional member on the driving member until it contacts with the follower member.

4. The combination with a follower member, of a positively rotated driving shaft, a .worm thereon, a-bushing in screwthreaded engagement with the worm, a sleeve nonrotatable and axially reciprocable on the bushing, and means for yieldingly forcing thesleeve into contact With'the follower member when the inertia of the bushing causes the latter to shift along the wormwhen the latter is operated.

5. The combination with a follower memher, of a positively rotated worm, a bushing loosely screwthreaded on the worm, .a sleeve non-rotatable and axially reciprocable on the bushing, a spring encircling the bushing andyieldably forcing the sleeve in one direction, the inertia of the bushing causing the latter to shift, the initial rotation of the worm with the follower member and the spring operating to hold the sleeve in yielding engagement with thefollower member and the bushing in engagement with the worm when the sleeve is operated.

6. The combination with a follower member, of a positively rotatable driven member,

in parallel relation thereto, a worm on the driving member, a bushing in screwthreaded engagement with the worm, a sleeve nonrotatable and axially reciprocable on the bushing provided with a face adapted to contact with the face of the follower memher, a spring encircling the bushing and abutting the sleeve, and a nut on the bushing acting as a stop for'the spring, the bushing beingadapted to shift along the worm when the latter is rotated until the sleeve contacts with the follower member, and the spring being adapted to retain the bushing in nonrc-tatable engagement with the worm when the sleeve is in frictional engagement with the follower member.

7. The combination with a starter and an;

explosive engine, having a rotatable member adapted to turn the engine and be turned thereby, of a worm positively driven by the starter, a bushing in screwthreaded and rotatable. engagement 'on the worm, a sleeve longitudirially reciprocable on the bushing adapted to engage frictionally on the rotatable member of the engine, a thrust nut adjustably mounted on the bushing, and a spring in compression between the thrust nut and the sleeve, the bushing being adapted to be shifted along the worm when the bushing loosely screwthreaded on the worm,

the inertia of which causes the bushing to shift alon the worm until arrested, a sleeve nonrotata le and longitudinally shiftable on the bushing, a thrust'nut adjustably secured on the bushing, and a spring in com pression between the thrust nut and sleeve adapted to maintain the latter in yielding contact with the rotatable member of the motor when the bushing shifts into operative relation to the latter and simultaneously therewith to hold the bushing in non-rotatable engagement with the worm.

In testimony whereof I 'aflix my signature in presence of two witnesses.

- JOHN T. TRUMBLE.

Witnesses:

FRED A. CORBRILLE, ANNA M. Donn. 

